The ternary system of yBiGaO(3)-(1-x-y)BiScO(3)-xPbTiO(3) (BGS-PT) ceramics was prepared by using conventional mixing oxide processing. X-ray diffraction analysis revealed that the BGS-PT ceramics showed the perovskite structure. The Curie temperature (TC) of BGSPT ceramics was found to increase with increasing BiGaO3 content. However, a larger BiGaO3 content led to sharply decreased piezoelectric properties, and the secondary phase was formed in the BGS-PT system. BGS-PT ceramics with x = 0.56, y = 0.19 showed a high Curie temperature T(C) and a large piezoelectric constant d(33) of 501??C and 152 pC/N, respectively. The high T(C) of BGS-PT ceramics with usable piezoelectric properties suggests future high-temperature applications.